Signal device



July 31, 1928. 1,679,011

R. G. WIDMYER S IGNAL DEVICE Filed June 1926 WVBWOR ROBERTGNWDMYER QQJ/ AWTORNEY Patented July 31, 1928; v

' 1 UNITED STATES PATENT OFFICE.

ROBERT G. 'WHJMYER, OF IRWIN, PENNSYLVANIA, ASSIGNOR TO THE WESTINGHOUSE AIR BRAKE COMPANY, OF WILMERDING, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

SIGNAL DEVICE.

Application filed June 5,

This invention relates to sound producing devices, and more particularly to the type employing a vibratory diaphragm.

The principal ob]ect of my invention .15

6 to provide an improved fluid pressure operated sound producing'devic'e of the above t e.

fn the accompanying drawing, the single figure is a central sectional view of a sound 1 producing device embodying my inventlon. The sound producing device may comprise a casing 1 having a chamber 2 wh1ch is open to a flexible diaphragm 3, said diaphragm being clamped in position by a cover plate 4, which is secured to the casing 1 by screws 5.

The casing 1 is provided with a threaded opening at the side opposite the diaphragm 3, into which is screwed a resonance tube 6. Said tube having an enlarged port1on 7 forming a shoulder ada ted to engage the end face of the threa ed portion of the casing 1. Secured to the tube 6 1s a suitable amplifyin horn 8. Y

When the tu e 6 is screwed down so that the shoulder thereof engages the end of the threaded portion of the casing, the free end of the tube just engages the diaphragm 3.

Secured to the central portion of the dia- 3 phragm 3 and extending into the open end of the tube 6 is a weight 9. The chamber 2 is connected to a pipe 10, through which fluid under pressure is supplied to said chamber, and preferably the pipe 10 is secured .to a plug 11 having screw-threaded engagement in the casing 1 and having a restricted port 12 through which fluid 1s supplied from pipe 10 to chamber 2.

In operation, when fluid under pressure is supplied to pipe 10, fluid flows through the restricted passage 12 into chamber 2 and the pressure of fluid in chamben2 builds up so that the diaphragm 3 ismoved out wardly. y

In moving out, communication is opened from chamber 2 to the space Withinthe tube 6. The pressure in said chamber is then uickly reduced, since the rate of flow t rough the restricted port 12 is consider 60 ably less than the rate of flow from chamber 2 to the tube 6. The ressure on the diaphragm 3 being thus relieved, said diaphragm returns to its position engaging the 1926. Serial No. 113,884.

The opening movement plified by the usual operation of the horn 8.

The addition of the weighted member 9 to the diaphragm 3 makes it necessary for the fluid pressure to be built up to a higher point before the diaphragm will move from engagement with the end of the tube 6, than would be the case with an unweighted diaphragm, but when the-diaphragm does move, the higher pressure causes a greater movement of the diaphragm and consequently, a greater amount of potential energy is stored up, so that the return movement of the diaphragm is effected more forcibly and a tighter engagement with the tube 6 is the result. A more positive opening and closing movement of the diaphragm is thus assured. In fact, it has been found that a diaphragm not provided with a weighted portion, tends to remain open and thus fail to vibrate.

An opening 13 is provided in the cover plate 4, so that the chamber at the outer vent tube normally in pressureless engage- I ment with said diaphragm and controlling communication from tube. a

2. A sound producing device comprising a casing having a chamber, a flexible diaphragm associated with said casing and subjectcto the pressure of fluid in said chamber,

said chamber to said a weight vcarried by said diaphragm for regulating the vibratory action of said diaphragm, and a vent tube normally adapted to seaton said diaphragm and controlling communication from said chamber to said. tube, said diaphragm exerting pressure on said tube only when the diaphragm is vibrating.

3. A sound producing device comprising a casing having a chamber adapted to be supplied with fluid under pressure, a tube open to the atmosphere and extending into said chamber, a flexible diaphragm normally seating Without pressure against the end of' said tube and controlling communication from said chamber to said tube, and a weight attached to said diaphragm for regulating the vibratory action of the diaphragm.

4. A'sound producing device comprising a casing having a chamber adapted'to be supplied with fluid under pressure, a flexible diaphragm secured to said casing and subject to the pressure of fluid in said chamber, a vent tube extendin into said chamber and having its end norma 1y engaging the central portion of said diaphragm without pressure being exerted by said diaphragm on said tube, and a Weight secured to said diaphragm at its central portion. and extending into said tube for regulating the vibratory action of said diaphragm.

5. A sound producing device comprising a casing having a chamber adapted to bev supplied with fluid under pressure, a flexible diaphragm, subject to the pressure of fluid in my hand,

' ROBERT WIDMYER. 

